2. An evolving historical perspective* The evolution of epidemiology into a science of the distribution of disease in populations and evaluation of interventions for disease prevention and therapy. Why study history [and herstory]? To understand a condition or event, we need to understand where it came from. To learn the lessons of the past To broaden our awareness from contemporary views by gaining perspective What is history? History, according to Edward Hallett Carr, is a “continuous process of interaction between the historian and his facts, an unending dialogue between the present and the past”* Propositions from studying history of epidemiology 1. Life has not always been the way it is in the developed countries today. 2. Scientific understanding of disease and the factors that affect it is largely a product of the last 150 years, with very rapid advances in the last half-century.. 3. Epidemiologic studies have not always been like ______ (insert the name of your favorite epidemiologic study). 4. There are many histories of epidemiology − History of health and disease − History of ideas and concepts − History of methods − History of knowledge gained through these concepts and methods − History of teachers and students − History of organizations and actions A brief history of public health Community attempts to prevent and limit the spread of disease go back to antiquity. For example, religious traditions against eating pork and shellfish reflect the special hazards of eating those foods * The following material draws heavily on lectures at the UNC Department of Epidemiology by Drs. Abraham Lilienfeld (1984) and Joellen Schildkraut (1989, 1990, 1991). * Carr, Edward Hallett. What is history. NY, Knopf, 1963, taken from the George Macaulay Trevelyan Lectures in the University of Cambridge in 1961, p.35. _____________________________________________________________________________________________ www.epidemiolog.net, © Victor J. Schoenbach 1999, 2000 2. Historical perspective - 17 rev. 8/21/2000, 3/9/2001, 5/20/2003 when inadequately preserved or prepared. As often happens in public health, even without an understanding of the underlying etiology, effective preventive measures can be taken. Successes in prevention reinforce the concept that disease can be prevented through human action other than prayers and sacrifices to the gods, which in turn encourages additional attempts at prevention. By the 1600’s, the practices of isolation and quarantine had begun to be employed to prevent the spread of certain diseases; by the 1800’s these practices had become common in the American colonies. Methods of smallpox inoculation also began to be used and apparently mitigated some epidemics, even before Edward Jenner's introduction of a safe vaccine based on cowpox virus. With the 19th century came two dramatic advances in the effectiveness of public health – “the great sanitary awakening” (Winslow, quoted in The Future of Public Health [FPH]: 58) and the advent of bacteriology and the germ theory. Those of us who see all progress in the field of health in terms of laboratory discoveries and medicines have not had the experience of living in a 19th century city. In New York City, piles of garbage two-three feet high were accompanied by epidemic smallpox and typhus. The crowding, poverty, filth, and lack of basic sanitation in the working class districts of the growing cities provided efficient breeding grounds for communicable diseases. Diseases that formerly arrived from outside to cause epidemics in basically healthy populations now became permanent residents. Quarantine and isolation, which were somewhat effective against individual cases and illness brought by travelers, were inadequate against mass endemic disease. Moreover, industrialization and urbanization brought people of different classes geographically closer. No longer able to escape to their country estates, well-to-do families also fell prey to the highly contagious diseases that incubated among the working class. The shared vulnerability and the succession of reports of conditions in the working class supported the view that while poverty might still reflect individual weakness and moral defects, society nevertheless had to take actions to improve conditions. In England, the Poor Law Commission led by Edwin Chadwick studied the English health of the working class. Their famous – and controversial – General Report on the Sanitary Conditions of the Labouring Population of Great Britain presented a “damning and fully documented indictment of the appalling conditions” (Chave, in FPH: 59-60). The studies revealed that the average age at death for laborers was 16 years. For tradesmen it was 22 years; for the gentry, 36 years. In London more than half of the working class died before their fifth birthday (Winslow, in FPH). A comparable document in the United States was Lemuel Shattuck's 1850 Report of the Massachusetts Sanitary Commission. Unlike Chadwick's report, however, Shattuck's report went largely ignored due to the political turmoil in the United States. After the Civil War, though, many of its recommendations were adopted, and it is now regarded as one of the most influential American public health documents (FPH: 61). Though controversial in many ways, sanitary reforms fit reasonably well with the moral views of the time. Much of the scientific rationale for the reforms – the relatively nonspecific model by which filth and putrid matter gave off emanations (miasma) that gave rise to disease – has only modest _____________________________________________________________________________________________ www.epidemiolog.net, © Victor J. Schoenbach 1999, 2000 2. Historical perspective - 18 rev. 8/21/2000, 3/9/2001, 5/20/2003 correspondence to modern biological understanding. Nevertheless, many of the reforms did reduce the transmission of disease and were therefore effective. But the advance in understanding of infectious disease that constituted the arrival of the bacteriologic era at the end of the century dramatically increased the effectiveness of public health action. In one dramatic example, mosquito control brought the number of yellow fever deaths in Havana from 305 to 6 in a single year (Winslow, in FPH: 65). Cholera, typhoid fever, and tuberculosis, the great scourges of humanity, rapidly came under control in the industrialized countries. Time line for the history of public health and epidemiology. Antiquity Concepts of health closely tied to religion (e.g., Old Testament) Greek writers draw links to environmental factors (e.g., Hippocrates) Romans associate plumbism with wine from lead-glazed pottery 1334 Petrarch introduces the concept of comparison and indeed of a clinical trial 1603 John Graunt – Bills of Mortality and the “law of mortality”. The first life table, giving the probability of dying at each age. 1700 Bernadino Ramazzini – “father of occupational epidemiology”; also breast cancer in nuns 1706-1777 Francois Bossier de Lacroix (known as Sauvages) – systematic classification of diseases (Nosologia Methodica) 1747 James Lind – scurvy experiment 1775 Percival Pott – scrotum cancer findings 1798 Edward Jenner – cowpox vaccination against smallpox 1787-1872 Pierre Charles Alexandre Louis (1787-1872) – the “Father of Epidemiology”, La methode numerique LaPlace, Poisson – the birth of statistics 1834 William Farr, William Guy, William Budd (all students of Louis) – founded the Statistical Society of London 1847 Ignaz Semmelweiss (Vienna) – discovers transmission and prevention of puerperal fever 1849 John Snow – waterborne transmission of cholera 1850 Epidemiological Society of London established 1851 John Grove – On the nature of epidemics (presented the germ theory) Oliver Wendell Holmes and George Shattuck, Jr. (and Shattuck's student, Edward Jarvis) – founded the American Statistical Society 1870 Beginning of the era of bacteriology 1887 The Hygienic Laboratory, forerunner of the U.S. National Institutes of Health, is created within the Marine Hospital Service in Staten Island, NY 1900 Yule – notion of spurious (i.e., nonsubstantive) correlations, “Simpson's paradox” 1914-1918 Joseph Goldberger studies pellagra 1920 Split between U.S. organized medicine and physicians interested in public health (the latter were interested in national health insurance; public health concern vs. individual concern) 1937 Austin Bradford Hill, Principles of Medical Statistics 1942 Office of Malaria Control in War Areas (in US; became Communicable Disease Center (CDC) in 1946, Center for Disease Control in 1970, Centers for Disease Control in 1980, _____________________________________________________________________________________________ www.epidemiolog.net, © Victor J. Schoenbach 1999, 2000 2. Historical perspective - 19 rev. 8/21/2000, 3/9/2001, 5/20/2003 and Centers for Disease Control and Prevention in 1992) 1948 World Health Organization (WHO) 1948 John Ryle becomes first chairman of social medicine at Oxford. Observed that physicians have curiously little concern with prevention. 1950's- Epidemiology successes – fluoride, tobacco, blood pressure and stroke, CHD risk factors, 1970's toxic shock syndrome, Legionnaire's disease, Reye’s syndrome, endometrial cancer and exogenous estrogens 1975 Lalonde Report (Canada) 1979 Healthy People U.S. and Health Objectives for the Nation 1988 U.S. Institute of Medicine Report of the Committee for the Study of the Future of Public Health – Public health system is in “disarray” – AIDS, injuries, teen pregnancies, Alzheimer's